#define _CRT_SECURE_NO_WARNINGS 1

#include <stdio.h>

struct S
{
	int _a : 30;
	int _b : 27;
	int _c : 5;
	int _d : 4;
};

int main()
{
	struct S s = { 0 };
	s._a = 10;//00001   010
	s._b = 12;//0000   1100
	s._c = 3;//000   00011
	s._d = 4;//0000   0100
	return 0;
}